$ { \left[\begin{array}{rrr}{4} & {1} & {-1} \\ {0} & {4} & {4}\end{array}\right]+\left[\begin{array}{rrr}{-2} & {-2} & {-1} \\ {3} & {-1} & {2}\end{array}\right] = {?} } $
To find the sum of two matrices, add the corresponding items between each matrix. ${\left[\begin{array}{rrr}{4}+{-2} & {1}+{-2} & {-1}+{-1} \\ {0}+{3} & {4}+{-1} & {4}+{2}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{rrr}{2} & {-1} & {-2} \\ {3} & {3} & {6}\end{array}\right]}$